Setaria sphacelata var. anceps


Scientific name

Setaria sphacelata (Schumach.) Stapf & C.E. Hubb. var. anceps (Stapf) Veldkamp

Synonyms

Setaria anceps Stapf
Setaria anceps Stapf var. sericea Stapf
Setaria sphacelata (Schumach.) Stapf & C.E. Hubb. var. sericea (Stapf) Clayton, nom. illeg.

Family/tribe

Family: Poaceae (alt. Gramineae) subfamily: Panicoideae tribe: Paniceae.

Common names

golden bristle grass, golden millet, South African pigeon grass, Rhodesian grass (southern Africa);  setaria (Australia);  capim-setária, napierzinho (Brazil);  pasto san juan (Costa Rica);  pasto miel (Ecuador);  fleo dorado (Mexico);  golden timothy (Zimbabwe).

Morphological description

Perennial tussock to 2 m tall, with short rhizomes.  Leaves bluish grey-green, leaf blades soft, glabrous, to 50 cm long and up to about 1 cm wide.  Lower parts of culms and the basal leaf-sheaths flattened.  Inflorescence a tightly contracted panicle producing a false spike , 7-25 cm long and about 8 mm wide (excluding the dense, radiating golden-yellow bristles);  stigmata purple or white.  Seeds average about 1.5 million/kg.

Distribution

Native to:
Africa:  Kenya, Tanzania, Uganda, Angola, Botswana, Namibia, South Africa, Swaziland, Benin, Burkina Faso, Cote D'Ivoire, Ghana, Guinea-Bissau - Cacheu, Mali, Mauritania, Nigeria, Senegal, Sierra Leone, Togo, Cameroon, Zaire.
Found on a wide range of habitats from wet areas (e.g. riparian land, swamp margins) to rocky hillsides.

Commonly planted in Africa, Asia, and Australia, becoming naturalised beyond the planted areas.

Uses/applications

Permanent pasture for grazing or cut and carry.  Forms stable groundcover for soil conservation.  Makes good silage.  Finer types suitable for hay .

Ecology

Soil requirements

Most commonly found on soils with texture ranging from sand to clay loam and light clay, but will grow on heavy clay.  Survives low fertility conditions but responds to improved fertility.  Not well adapted to alkaline or very acid soils, most wild collections coming from soils of pH 5.5-6.5.  Generally low salt tolerance.

Moisture

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Although mostly found in areas with rainfall down to about 750 mm/yr, it is generally only sown where annual rainfall exceeds 1,000 mm.  More tolerant of waterlogging and flooding than many tropical grasses.  Generally poor drought tolerance, although this varies with provenance .

Temperature

Best suited to non-equatorial conditions.  Found in its native environment from sea level to 3,300 m, most commonly between 600 and 2,700 m asl.  Grows best at about 18-22°C.  Moderate early season growth in the subtropics and upland tropics, with 'Narok' and 'Solander' producing up to four times the cool season yield of the other cultivars.  Frost tolerance varies with provenance/cultivar, with 'Narok' and 'Solander' the most frost tolerant, sustaining little leaf damage at grass temperatures down to -3°C (similar to Paspalum dilatatum ).  'Kazungula' is more cold tolerant than 'Nandi' in which plants are killed at -4°C.

Light

Moderate shade tolerance, producing to 60-70% of full light yield at 50% light.

Reproductive development

Flowering time varies markedly with strain and area of origin.  'Nandi' begins flowering in December (early summer) in the subtropics of Australia, continuing through to April or May, with a peak of flowering in January.  'Kazungula' flowers about a month later.

Defoliation

Fairly tolerant of cutting and grazing.  If grazed heavily, setaria is replaced by stoloniferous/rhizomatous grasses such as Digitaria didactyla and Paspalum notatum .  If N status is low, it declines more rapidly.

Fire

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Mostly not burnt, but will survive the occasional fire.  Higher basal area and tiller number under late burning compared with early or no burning.

Agronomy

Establishment

Fresh seed is dormant and should be stored for two months.  Normally sown at 2-5 kg/ha.  Like many small-seeded tropical grasses, seedlings are slow to develop, although 'Kazungula' establishes more rapidly than other cultivars.

Fertiliser

Normally planted with a basal NPK dressing.  Potassium uptake is very high and regular applications of K fertiliser may be necessary in low K soils to maintain vigour of associated species.  Responds well to nitrogen, producing about 30 kg DM and 3 kg CP per kg N applied.

Compatibility (with other species)

A very competitive species, suppressing most weeds once established.  In the first season, it can be suppressed by short-lived weeds, but assumes dominance in the second or third year.  Setaria combines well with legumes if soil fertility , particularly potassium, is maintained.  'Kazungula' is more competitive than other cultivars.

Companion species

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Grasses:  Normally not sown with other grasses.
Legumes:  Neonotonia wightii , Desmodium intortum , D. uncinatum , Macroptilium atropurpureum , Vigna parkeri , Lotus uliginosus , Trifolium repens.

Pests and diseases

Leaf spot caused by Pyricularia grisea affects 'Nandi' and 'Narok' under hot, humid conditions but usually not 'Kazungula'.  Fungal diseases caused by Tilletia echinosperma (bunt) in Kenya and Sphacelotheca sp. and Fusarium nivale var. majus in Zaire can seriously reduce seed crops.  The buffel grass seed caterpillar (Mampava rhodoneura) can also damage seed crops.  Attacked by insects such as army worm (Pseudaletia convecta in Australia and Spodoptera exempta in Africa) that attack other tropical grasses.

Ability to spread

Spreads effectively by seed, readily colonising disturbed areas such as roadsides.

Weed potential

Listed as a weed in some regions but rarely invades undisturbed areas.

Feeding value

Nutritive value

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Moisture levels in fresh growth often higher than in other tropical grasses, reaching levels >85%.  CP content of 6-20% depending on age of material and nitrogen fertilisation, with CP digestibility ranging from 44-77%.  DM digestibility values of about 70% have been recorded in young leafy 3-week regrowth, falling to 50-55% at 6-8 weeks.

Palatability/acceptability

Extremely palatable when young but becomes stemmy and unacceptable with maturity.

Toxicity

Oxalate is present in all cultivars, but varies with cultivar - 'Kazungula' > 'Narok' and 'Solander' > 'Nandi'.  Levels are higher in fresh growth, and exacerbated by N and K fertilisation.  Highest levels of oxalate occur at night, and the lowest in mid-afternoon.  Causes ill-thrift, lameness and swelling of the head bones or 'big head' disease (Osteodystrophia fibrosa) in equines.  Horses and donkeys should not be permitted to graze setaria for more than 1 month at a time.  It can also lead to 'milk fever' (Hypocalcaemia) in cattle grazing Setaria sphacelata var. anceps, particularly 'Kazungula'.  This can be treated with an injection of calcium borogluconate solution.  Cattle that have not grazed well fertilised setaria for some time should be introduced gradually to the setaria, before more regular exposure.  This allows them to develop a rumen flora that can detoxify oxalate.  'Grass staggers' (Hypomagnesaemia) can also occur, a disease caused by too little magnesium in the blood system, induced through low levels of Mg and high levels of K in the feed.  In dairy cows, 'grass staggers' is often a complication of 'milk fever'.  It is therefore wise to use a combined treatment of calcium borogluconate and magnesium hypophosphite.

Production potential

Dry matter

Annual dry-matter yields of about 26,000 kg/ha have been recorded from a well-fertilised, irrigated stand.  Yields of the order of 10,000-15,000 kg/ha are more common.

Animal production

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In the subtropics, steers continuously grazing setaria fertilised with 330 kg/ha N, and stocked at about 3 steers per hectare, can produce liveweight gains of 500-800 kg/ha per year.

Genetics/breeding

Cross-pollinating.  Mostly diploids (2n = 18) and tetraploids (2n = 36), although hexaploids, octoploids and rarely decaploids have been identified.

Seed production

Flowering occurs over a long period.  Presentation yields ranging from 40-560 kg seed/ha are quoted in the literature, although good commercial yields are usually of the order of 100 kg/ha.  Crops fertilised with 100-150 kg/ha N are usually direct headed when 10-15 percent of the seed has shattered.

Herbicide effects

Established setaria is tolerant of 2,4-D, dicamba and MCPA.  It can be controlled with glyphosate.

Strengths

  • Palatable.
  • Establishes easily from seed.
  • Persists under moderate grazing.
  • Adapted to a wide range of soils.
  • Tolerant of flooding and waterlogging .
  • Some lines frost tolerant.

Limitations

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  • Heavy spring/summer seeding reduces feed quality.
  • High oxalate levels can cause animal disease.
  • Not very drought tolerant.

Other comments

  

Selected references

Bogdan, A.V. (1977) Tropical Pasture and Fodder Plants (Grasses and Legumes). pp. 249-260. (Longman: London and New York).
Gibbs Russell, G.E., Watson, L., Koekemoer, M., Smook, L., Barker, N. P., Anderson, H.M. and Dallwitz, M.J. (1990) `Grasses of  Southern Africa'. Memoirs of the Botanical Survey of South  Africa No. 58 . Botanical Research Institute: Pretoria.
Hacker, J.B. (1992) Setaria sphacelata (Schumach.) Stapf & Hubbard ex M.B. Moss. In Mannetje, L. 't and Jones, R.M. (eds)  Plant Resources of South-East Asia No. 4. Forages. pp. 201-203. (Pudoc Scientific Publishers, Wageningen, the Netherlands).
Hacker, J.B. and Minson, D.J. (1972) Varietal differences in in vitro dry  matter digestibility in Setaria, and the effects of site, age, and  season. Australian Journal of Agricultural Research, 23, 959-967.
Jank, L., Quesenberry, K.H., Blount, A.R.S. and Mislevy, P. (2002) Selection in Setaria sphacelata for winter survival. New Zealand Journal of Agricultural Research, 45, 273-281.
Jones, R.J. and Jones, R.M. (1989) Liveweight gain from rotationally and  continuously grazed pastures of Narok setaria and Samford  rhodesgrass fertilized with nitrogen in southeast Queensland.  Tropical Grasslands, 23, 135-142.
Jones, R.M. and Jones, R.J. (2003) Effect of stocking rates on animal gain,  pasture yield and composition, and soil  properties from setaria- nitrogen and setaria-legume pastures in coastal south-east  Queensland. Tropical Grasslands, 37, 65-83.
Oram, R.N. (1986) Setaria sphacelata (Schumach.) Moss var. sericea  (Stapf) Clayton (setaria) cv. Solander (Reg. No. A-8a-5). Journal of the Australian Institute of Agricultural Science, 52, 180-181.

Internet links

Cultivars

Cultivars

Country/date released

Details

'Bua River' South Africa From Malawi, used for silage, hay or green chop.  Oxalate levels similar to those of 'Kazungula'.
'Du Toits Kraal' South Africa From Zimbabwe, recommended for areas with 500-700 mm rainfallDrought resistant and retains some greenness and palatability into winter.
'Kazungula' South Africa (1940s)
Australia (1962)
Tetraploid from Zambia.  Culms to 2 m tall.  Stigmas purple.  Developed for grazing and hay.  Coarser and more robust than 'Nandi'.  Flowers a month later and seed is slightly smaller than that of 'Nandi'.  Hardier and more adaptable, being particularly tolerant of waterlogging, yet growing on as little as 575 mm annual rainfall .  Used in more tropical environments in Australia.  Has a high sodium and potassium content, and higher oxalate content than other cultivars.  Under grazing, tends to be much stemmier than 'Nandi' unless grazing management is very good during flowering and seeding.
'Nandi'
(CPI 28709)
Kenya (1953)
Australia (1963)
Diploid from Baraton Nandi district in Kenya highlands.  Culms to 1.5 m tall.  Stigmas white.  More sensitive to frost and flowers earlier than 'Kazungula'.  Lowest oxalate content of Australian cultivars.  Establishes less readily than 'Narok' and 'Kazungula'.
'Narok'
(CPI 33452)
Australia (1969) Tetraploid from the Aberdares region of Kenya (altitude 2,190 m).  Culms to >1.8 m tall;  more robust than 'Nandi' but not as coarse as 'Kazungula'.  Stigmas usually purple, sometimes white.  Selected for improved winter production and frost tolerance .
'Nasiwa' Kenya Earlier flowering selection from 'Nandi'.
'Solander' Australia (1985) Tetraploid hybrid using frost tolerant accessions CPI 32930 (16%) and CPI 33452 (34%), and more robust frost susceptible accessions CPI 19915 (18%), CPI 16413 (24%) and var. splendida CPI 15899 (8%).  Culms to >1.8 m tall.  Stigmas purple, sometimes white.  Selected for winter yield, winter greenness and seed production (superior to that of 'Narok').
'Splenda' Australia (1981) Hybrid from crosses between the tetraploid var. splendida, CPI 15899, and two tetraploid accessions of var. sericea, CPI 19915 and CPI 16067.  Selected for seed production (up to 80 kg/ha cleaned seed) and conformity to var. splendida phenotype (late flowering and leafiness).  Later flowering than 'Kazungula', 'Nandi' and 'Narok'.  Well adapted to wet tropical situations but also of value in other tropical and subtropical regions with a rainfall exceeding 1,000 mm where dry periods do not exceed 3 months.  Not suitable for horses because of high oxalate concentration in the dry matter of young leaf about 4.7% (91% soluble).  Na and K concentrations were 0.74 (a Na accumulator) and 4.47% respectively.

Promising accessions

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Promising accessions

Country

Details

CPI 32847, CPI 32714 Australia (Queensland) Two hexaploids from near the Aberdare Mountains in Kenya.  Showed some salt tolerance;  also tolerated cool conditions.
CPI 32930 Australia (Queensland) More frost tolerant than 'Narok';  also better cool season growth, but lower annual yield.